Skip to main content

What is active data guard and How to enable stanby database is in read-only mode (Active standby)

What is active data guard and How to enable stanby database is in read-only mode (Active standby)??

If trying open the standby database in read only mode will get the below error.

SQL> ALTER DATABASE OPEN READ ONLY;
ALTER DATABASE OPEN READ ONLY
*
ERROR at line 1:
ORA-10456: cannot open standby database; media recovery session may be in progress.

1. First we need turf off the log apply process on the standby database. Using the below.

DGMGRL> edit database <stdby_dbname> set state=apply-off;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;

SQL> ALTER DATABASE OPEN READ ONLY;
SQL>Select name, open_mode, switchover_status, database_role from v$database;

Start apply process using Broker (OR) Manually in standby database.

DGMGRL> edit database <stdby_dbname> set state=apply-on;
SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

To disable the active data guard, the steps are the same:

1. DGMGRL> edit database stdby set state=apply-off; (OR) 
   SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
2. Shutdown the stdby database;
3. Startup mount the stdby database
4. DGMGRL> edit database stdby set state=apply-on; (OR) 
    SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE USING CURRENT LOGFILE DISCONNECT;

Labels:

Comments

Post a Comment

Popular posts from this blog

Issues and Solutions for Oracle 19c Grid Infrastructure Installation

     Common Issues and Solutions for Oracle 19c Grid Infrastructure Installation •       Check Log Files for Details Oracle installation issues often provide valuable clues in the log files. If the installer seems stuck or fails, check the following logs: ▪ Install log : /u01/app/oraInventory/logs/installActions<date>.log •       ▪ Grid Infrastructure log : $ORACLE_BASE/cfgtoollogs/ •         •       These logs can provide error messages and help identify the exact issue. •         •        Check Permissions and Ownership Verify that the Oracle Grid Infrastructure installation directories have the correct ownership and permissions. •        For example: •        Make sure the grid user has permission to write to the directories where the i...
Post a Comment
Read more

How to Improve Oracle Data Pump Performance - IMPDP

  How to Improve Oracle Data Pump Performance:- Use Parallelism : Set the PARALLEL parameter to at least 2 * number of CPUs . This allows multiple worker processes to perform tasks simultaneously, speeding up both export and import processes. Example: PARALLEL=4 for a system with 2 CPUs. Perform Import Using NETWORK_LINK : Use the NETWORK_LINK parameter to import data directly from the source database. This method is particularly helpful when space is constrained, as it streams the data without needing to generate dump files on the source. It can also reduce time compared to exporting and then importing, as data is streamed directly from the source to the target database. Disable Archivelog Mode (Standalone Databases) : For standalone databases, temporarily disable archive logging during the import process. Import operations can generate a lot of redo logs, slowing down the import. Disabling...
Post a Comment
Read more

Difference between AWR, ADDM and ASH reports

AWR: Automatic Workload Repository gathers, processes and maintains performance stats used for problem detection and self-tuning the databases. Different Components that uses AWR are: Automatic Database Diagnostic Monitor Undo Advisor SQL Tuning Advisor Segment Advisor Different types of AWR Reports for different purposes: For Single Instance Environment: @$ORACLE_HOME/rdbms/admin/awrrpt.sql For Oracle RAC Environment : @$ORACLE_HOME/rdbms/admin/awrgrpt.sql For a particular SQL Statement : @$ORACLE_HOME/rdbms/admin/awrsqrpt.sql For Comparing the reports : @$ORACLE_HOME/rdbms/admin/awrddrpt.sql ADDM: Automatic Database Diagnostic Monitoring Report analyzes the AWR data on a regular basis, to give you overview of the root cause of the problem which is affecting your database’s performance. It also provides suggestions or recommendations for rectifying any problem identified and lists the areas which are having no issues. ADDM recommends multiple solutions for the DBA to choose from which...
Post a Comment
Read more